Locomotive draft device



L. PRAT.

LOCOMOTIVE DRAFT DEVICE. APPLICATION FILED no.4, 1917.

Patented Mar. 28, 1922.

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L. PHAT.

LOCOMOTIVE DRAFT DEVICE. APPLICATION FILED DEC. 4. 1917.

2 sums-$11551 2.

Fig 5 Fig 7 Mar an stares @ATENT LOUIS PHAT, OF PARIS, FRANCE.

LOCOMOTIVE DRAFT DEVICE.

Application filed December 4, 1917.

Specification of Letters Patent.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 31521, STAT. L.,1313.)

To all whom. it may concern Be it known that T. LOUIS Paar. a citizen ofthe Republicot France, and a resident of Paris, France, have inventedcertain limprovements in Locomotive Draft Devices, (for which I havefiled applications in France Nov. 15, 1916, Patent No. @3363, and inSwitzerland Dec. 29, 1916, No. 88,- 423,) of which the following is aspecification. 7

This invention relates to means for inducing draught in the boilers oflocomotive, portable and semi-portable engines and other apparatus inwhich the space available for the smoke stacks is restricted.

In apparatus of this kind the usual method is to increase or ensure thedraughtby means of a jet of exhaust steam, during normal working, (oreven of live steam under certain circumstances) which presentsconsiderable disadvantages; In the first place, the efiiciency obtainedis poor, asis always the case with steam blowers; (2.) The necessity ofobtaining a powerful draught calls for a sufiiciently high steampressure, and since, where the exhaust is used for creatln the draftthis pressure is exact-1y the back pressure on the piston, the

draught can only be obtained at the expense of the efliciency of thelocomotive; (3.) Inasmuch as the steam which supplies the blower isderived from the exhaust of a reciprocating engine the draughtis notconstant but fluctuates in accordance with the strokes of the piston;(4.) With a steamturbine locomotive, as it is almost essential to workas a condensing engine, no exhaust steam is available and consequently ablower worked merely by live steam is the only kind possible in thiscase; (5.) However well arranged the steam blower may be, the draught inthe fire-tubes of the boiler is irregular.

The efliciencv of the upper tubes is always appreciably better than thatof the lower tubes, and it has been found that by plug-' panyingdrawings wherein each view is diagrammatic and shows parts broken awayand parts in section, and in which: Fig. 1 is a side elevation insection showing the boiler and smoke stack of a locomotive provided withone embodiment of the invention, and Fig". 2 is a top plan view of same.Figs. 3 and i are similar views of a second embodb ment; Figs. 5 and 6or". a third embodiment; Figs, 7 and 8 of a. fourth embodiment; Fig. 9shows 'a detail view of an injection ring of auxiliary steam.

The smoke stack is formed of a pipe, comprising an inwardly taperingportion (a, situated next the smoke box (Z, with which it is connected,a mixing chamber 7), and an out wardly flaring portion 0.

Concentric with the portion a. is the outlet a ot a fan f, whose intakepipe terminates in a trumpet shaped mouth it. (Figs. 1 and 2 and Figs..3 and a), which faces the lower tubes of the boiler. The fan is drivenby a steam turbine 10, which may be supplied with steam from anysuitable source, such as with live steam drawn from the boiler of thelocomotive as through the pipe ll.

The fan when in operation draws in av portion of the smoke-box gasesdirectly, through its intake pipe and discharges them through the outlet(2, the smoke stack a, b c formingan ejector which also aspirates fromthe smoke box (Z, the result being the production of a strong draught inthe smoke stack under conditions, as regards efiiciency, that are betterthan is the case with the usual steam blower. In fact, the energy storedup in the steam is utilized to drive the fan motor to the best advanta1e whereas when a bloweris used the efficiency of the steam is very low.

The pipe 9 is preferably made telescopic (Fig. 1) to enable the trumpetshaped mouth it to be brought down to the desired level for drawing thegases from the lowest tubes. With the same end in view the tan intakemay be provided with a damper 6 (Figs. 5 and 6) adapted to rotate on ahorizontal axis as indicated by the curved dotted line in Figure 8, sothat by altering its position the relative proportions of the gasaspirated by the ejector and that drawn in directly by the fan may becontrolled.

The fan aspirates either axially, as e. 9. Figs. 1' and 2 ortangentiallyas in the other figures and its axis may be vertical (as Figs. 1 and 2)or horizontal (as in the other figures.)

Two or more fans as shown in Figures 2 and 8 driven by the same'motor orby different motors, may be employed instead of a single tan, if it bedesired to obviate the risk of stoppages.

There may be employed in combination with the above described means forproducing draught, an auxiliary device comprising a jet of live steamfor preventing any failure of draught in case the fans are put out oraction, which jet, however, may at times be caused to operate conjointlywith the aspiration by the fans, in order for instance to increase thedraught on up grades. The jets of live steam are delivered eitherthrough nozzles situated 'in the axes of the discharge pipes 0 (seeFigs. a and 6), or else through a series of holes 70 located in a ring Zplaced around these pipes (see Figs-l and 9). Said holes are better seenin Fig. 9 which is an enlarged cross section of the pipe 6 and ring Z.

In a constructional form oi theapparatus which possesses specialadvantages a plurality of smoke stacks, provided with injection pipesconnected with one or more fans are employed, said smoke stacks beingadapted to operate singly or togetherywhen it .is desired to use certainof the units as a standby or to strengthen the draught at certain times.

In Figs. 4 and 6 the single fan 7 is provided with two discharge pipes eand two smoke stacks.

Fig. 2 shows two fans fprovided each with a single discharge pipe 0 andeach discharg ing into a smoke stack a, b, 0.

Finally, Fig. 8 shews two fans, each arranged to supply two smokestacks. but adapted to deliver independently into several smoke stacks.

The advantage of this subdivision is that the length of the smoke stackscan. be. reduced, and they can therefore be installed in a smallerspace, and, it necessary, vertically.

Having'now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:

1. In a. locomotive a boiler having fire tubes or fines, a horizontalsmoke stack etitending backward over the boiler, said smoke stackcomprising a. convergent portion opening into a divergent portionthrough a constricted area, a rotary fan pla ed at the upperpart of thefire tubes. a passage loading a portion otthc smoke to thetan, an outletfrom the fan opening into the constricted part of theconvergent-divergent stack. and v a smoke chamber in front of the boilertubes 2. In a locomotive a boiler having fire tubes or flues, ahorizontal smoke stack extending backward over the boiler, said smokestack comprising a convergent portion opening into a divergent portionthrough a constricted part, a rotary fan placed at the upper part of thetire tubes, a passage leading a portion of the smoke to the tan, anoutlet from the tan opening into the constricted part of theconvergent-divergent stack, a jet of steam also discharging into saidconstricted part, and a smoke chamber in front of the boiler tubesleading the remainder oi. the smoke into the convergent portion of thestack. 7 p

3. In a locomotive, a boiler having lire tubes or flues, twosmoke-stacks extending horizontally backward over the boiler and eachcomprising a convergent portion leading into a divergent portion, arotary fan placed at the upper part of the tubes and having an outletdivided into two branch nozzles opening into theconstricted parts ofsaid two smoke-stacksrespectively, a passage leading a ,portion of thesmoketo the tan, and a smoke chamber in front of the boiler tubesleading the remainder of the smoke around each of the branch nozzles ofthe tan into the respective smoke stacks.

fl. In a locomotive, a boiler having fire tubes or fines, and a smokechamber, a horizontal smoke stack extending backward over the boiler,said stack comprising a convergent portion opening into a divergentportion through a constricted area, a rotary fan placed at the upperpart of the smoke chamber, and a pipe adaptedgtolead apo'rtion of thesmoke from the fines to the fans, said pipe being composed oi telescopicsections adapted to hold the intake opening of. the pipe at'diiferentlevels opposite the exit openings of the fines. V

5. In a locomotive having boiler tubes. a chamber in front of the boilertubes into which they discharge, a smoke stack opening out of" saidchamber and extending backward over the boiler, said smoke stackcomprising a convergent portion next said chamber opening into a largerdivergent portion, a pipe made in telescopingsections within saidchamberhaving a vertically adjust-able receiving opening 72/ opposite theboiler tubes andfacing the same and extending upward to discharge intosaid smoke stack, and means associated'wi'th said pipe for forcing gasesthrough the same into said smoke stack. 7 v In testimonv whereof, Iafiix my signature, in presence oitwo witnesses. r

r v LOUIS PRAT.

'Witness'esr I L. E. Parsons. V

ALBERT Nouns.

